Expiration Dates for Insulin

Novolog, to be precise.

The product literature says it's good for a month (about) once it's opened. Does this correspond well to actual experience? I'd appreciate some feedback from experienced users.



Insulin is suppose to last for 28 days when it's opened. If for some reason it's exposed to extreme heat or cold then it can become unstable.

I had a wierd situation, I had one bottle I'd questioned at first, maybe it was a bad site or something but it didn't seem to work, new site worked ok so I went with it. It was close to the end of the bottle and I knew there might be some risk of what I sort of refer to as "bottle-fade", where the end of the bottle doesn't work as well as the beginning but whatever. Then I looked closely and was like "hmmm, is that even enough?" and went "whatever". Then we drove to St. Louis on Saturday and, right when we got there, I realized I'd tossed the bag in the trunk. And it was 105 out! Yikes, I was sure I, along with my insulin, was cooked! I went out anyway, had some fun, came back to the hotel and had to do a site change and woke up and was fine!

Before I started pumping I used 3 pins at once.
I would carry one and had one at home and work.
They would last about 90 days.

I use Humalog and usually I dont have any problems when I get to the end of a vial, but I sure have with this one. Just kinda running stubbornly high. Got annoyed, changed the infusion site, and opened a fresh new bottle of insulin. See what happens now.

Some more background to give the question better context: at the very small amounts I use, there is absolutely no way the vial will be used up before 30 days. So what I'm wondering is, how long does it really last as opposed to how long they say it lasts. I'm interested in your actual, real world experience on this.

10 units a day will empty a pin in less than 24-25 days, every injection also burns a unit to prime the needle. 300Unpins or cartridges will reduce wast.If you need to
add correction insulin to your bolus buy a pediatric pin it will dose 1/2u.

I use insulin in vials and they often last more than a month. I have never had a problem with them, right down to the very last drop. (And I do get that one out.)

If there is a problem with the insulin, it won't take long to show up. The next time you test, you will have a good indication. Of course depending on what else is happening, it might take a couple of injections and tests.

But for the price of the stuff, I can't afford to toss it in the garbage.

One of my micro jokes goes like this.

We really need more dates than just the "best before" date on food packaging. Not everyone can afford or even wants the absolute best. How about a "still sort of ok" date followed by "take a chance until?"

There are a lot of good pages on the net about how medications are usually good for much longer than the expiry date. The US army started testing them, and most of them were at least 90% effective after 3 years if they had a 1 year expiry date.

Insulin is one of the ones where the expiry date is supposed to be close, but I take good care of mine and have not had the slightest problem.

Insulin itself doesn't go bad especially if it's refrigerated. The 30 day discard instruction is due to the possibility of contamination. The more you tap the vial the more likely it will become contaminated.

Gary S

Good to know. I keep it constantly refrigerated and I swap the vial with alcohol before each use. That ought to improve the odds as much as possible.

I have used my vials until they are empty every time, with no ill effects. It is a waste to toss them after 28 days unless you aren't satisfied with the results. An endo I used to see said that the companies put an expiration date and say to toss it in 28 days to protect their liability if the insulin doesn't work in that time frame. I always kept the opened vial in the 'frig with the unopened ones. I find using pens now that they don't last as long b/c there is only 300U as opposed to the 1000u in a vial.

Yes, I understand that if this ever does become a problem I can simply buy pen refills instead of ordinary vials. But I suspect that if the vials are cared for properly they will be just fine. Time and experience will tell. I'm still new to this (obviously).

P.S. At the dosages I am presently using, even a pen cartridge might not get used up in 30 days. Anyway, it's good to have options.

Looking at the forest and not simply the trees, the truly important thing is that the insulin is doing what I want it to. That is worth almost any degree of inconvenience.

Hi David. In the summertime, both my Apidra and Levemir will sometimes quit at two weeks. I use an Apidra vial and a Levemir pen, and keep them both in the fridge after opening. I blame their transportation before I get them home for the occasional short-life. (I transport them in an insulated, cool carrier.) I get them from a local pharmacy, which I trust, but before that? Still I prefer these two to other insulin types (actually, Levemir is the only basal that doesn't keep me in constant lows), and so far have managed to keep enough of a backup for both to be O.K. I have used Novolog, which works more slowly for me than Apidra, but the Novalog seems to me to be longer-lasting and less temperature sensitive than Apidra. I don't know if any of that is a help!

Yes, you can use the cartridges like a vial. It's exactly as you said it ...you just pull it out without injecting air.

I used it as long as it lasts but in general I think that the insulin will be fine as long as it's kept in the right conditions. Just keep it away from a hot place and other things that might make it more sensitive.